1. Field of the Invention
The present invention relates to a bumper reinforcing member provided on the inner surface side of a vehicle""s bumper fascia to absorb impact applied to the bumper.
2. Description of the Related Art
FIG. 4 shows an impact absorbing construction at the front or rear of a passenger vehicle or the like. As shown in the diagram, a bumper fascia 102 is provided on the lower side of a vehicle body 100. A reinforcing member 104 for absorbing impacts is provided between the vehicle and the inside 6f the bumper fascia 102. The reinforcing member 104 is mounted on a side member 108 via a bracket 106. In recent years, resins are being used more and more in place of metal materials to construct the reinforcing member 104 in order to form a more lightweight reinforcing member 104 with better corrosion resistance.
This type of reinforcing member is formed in an arch construction that is expanded in the front center portion. The member is mounted to the vehicle on the widthwise ends. Hence, when an object impacts the bumper, the impact transferred to the vehicle can be alleviated by the elastic deformation of the reinforcing member and further through plastic deformation, which functions to absorb energy.
A resinous bumper reinforcing member of this type is disclosed in Japanese laid-open patent publication No. 2000-52899. This bumper reinforcing member comprises a frame that is open on the front and back surfaces, two partitioning plates that partition the space in the frame into a center space in the widthwise direction of the vehicle and two end spaces, a front surface plate covering the front side of the center space, and rear surface plates covering the rear sides of the end spaces.
Tests performed to learn the impact absorbing capacity of the bumper mainly include a pole test and a barrier test. The pole test, illustrated in FIG. 5A forces a pole 110 having a diameter of 178 mm to collide with the center section of the bumper in a horizontal direction and at a prescribed speed. The barrier test shown in FIG. 5B forces a flat barrier 120 to collide with the entire widthwise surface of the bumper at a prescribed speed. By performing the collisions in each test, it is possible to take measurements of the force received at the mounting parts 130 on the rear end of the reinforcing member 104 and to measure the amount of deformation in the reinforcing member 104 itself. In the pole test, a pole-shaped object is made to collide with the bumper in approximately the center of the bumper in the widthwise direction, applying a force similar to a point load. Therefore, the amount of deformation is great. In the barrier test, a plate-shaped object is collided with the entire front surface of the bumper, applying a force similar to a surface load. Therefore, the load generated at the mounting points is great. As a result, there is demand for a bumper having a satisfactory impact absorbing capacity for both the pole and barrier tests. It is necessary to further improve the balance in impact absorbing capacity for these two tests of different quality from that described in the above application.
In view of the foregoing, it is an object of the present invention to provide a bumper reinforcing member having sufficient and well-balanced impact absorbing qualities for both point loads and surface loads.
These objects and others will be attained by a bumper reinforcing member formed of a resinous material and provided between a bumper fascia and a vehicle body, the member comprising a plurality of horizontal plates disposed approximately along a horizontal plane; and a plurality of vertical plates integrally connected to the horizontal plates and disposed approximately along a vertical plane. A line connecting a load input position at the front end of the horizontal plate on the bumper fascia side and a mounting position on the rear of the reinforcing member on the vehicle body side forms an angle with the horizontal plane.
In the pole test, the bumper reinforcing member should be able to absorb the concentrated load applied in the front center of the bumper with as little deformation as possible. The bumper reinforcing member of the present invention has high rigidity due to the construction of the horizontal plates that can minimize the amount of deformation in the pole test. In the barrier test, a surface load is applied in the horizontal direction to the front surface of the bumper. In this case, the bumper reinforcing member must soften impact transferred to the vehicle through the highly rigid horizontal plates. In the bumper reinforcing member of the present invention, a line connecting the point in which the load is input and the rear mounting part of the reinforcing member forms an angle with the horizontal plane, enabling the horizontal plates to easily spread and flexibly absorb the surface load. In this way, the bumper reinforcing member of the present invention can provide satisfactory impact absorbing qualities for the barrier test, while maintaining the impact absorbing capacity for the pole test.
According to another aspect of the present invention, the line connecting the load input position to the mounting position is parallel to the horizontal plane near the widthwise center of the bumper reinforcing member but forms an angle with the horizontal plane at the ends of the bumper reinforcing member, the angle growing larger the farther away from the center.
With this construction, the bumper reinforcing member can achieve sufficient capacity for absorbing the concentrated impact by providing horizontal plates along the direction in which the load is applied in the pole test at the center section of the bumper. The line connecting the position of load input on the front end of the bumper reinforcing member and the mounting positions on the rear end form an angle with the horizontal plane that grows larger toward the ends of the bumper reinforcing member. Accordingly, the bumper reinforcing member can flexibly absorb the load on both widthwise ends of the bumper reinforcing member and achieves a well-balanced capacity for absorbing impacts in both the pole test and the barrier test.
Further, the sides of the horizontal plates on the widthwise ends of the bumper reinforcing member are open. With this construction, the bumper reinforcing member can provide flexible impact absorbing properties for surface loads on both widthwise ends of the bumper.
Further, the horizontal plates are configured such that the front ends of the horizontal plates themselves form an angle with the horizontal plane. With this construction, the bumper reinforcing member can be manufactured such that the line connecting the load input position to the mounting positions on the back of the bumper reinforcing member forms an angle with the horizontal plane, that is direction of load input.
According to another aspect of the present invention, extension parts forming an angle with the horizontal plane are added to the front ends of the horizontal plates that are positioned approximately along the horizontal p lane. With this construction, the input position of impact is the front ends of the extension parts that form an angle with the horizontal plane. Therefore, the bumper reinforcing member can be constructed such that the line connecting the load input position to the mounting positions on the rear end forms an angle with the horizontal plane (direction of load input).
According to another aspect of the present invention, vertically extending ribs are added to the front ends of the horizontal plates that are positioned approximately along the horizontal plane. With this construction, it is possible to form an bumper reinforcing member such that the line connecting the input position of impact and the mounting positions on the rear end forms an angle with the horizontal plane (direction of load input).
The above and other objects, features, and advantages of the present invention will be apparent from the following description when taken in conjunction with the accompanying drawings which illustrates preferred embodiments of the present invention by way of example.